- 75g/2¾oz butter
- 500g/1lb 2oz leeks, sliced and washed
- 3 sprigs fresh thyme, leaves picked
- 150ml/5fl oz white wine
- 200ml/7fl oz double cream
- 75g/2¾oz brioche loaf, cut into 1cm/½in cubes
- 50g/1¾oz Gruyère, finely grated
- salt and freshly ground black pepper
- Preheat the oven to 200C/180C Fan/Gas 6.
- Heat 50g/1¾oz of the butter in a frying pan and fry the leeks and thyme for 2-3 minutes, or until softened.
- Add the wine and cook until the volume of the liquid has reduced by two-thirds. Add the cream and reduce again by half. Season with salt and pepper and pour into an ovenproof dish.
- Heat a separate frying pan until hot. Add the remaining butter and the brioche. Cook until golden-brown on all sides. Season with salt and pepper and scatter over the top of the leeks.
- Sprinkle the cheese on top of the dish and cook in the oven for 20-30 minutes, or until golden-brown and bubbling.